Abstract: A global email classification system enables email messages to be classified based on various factors into many categories. The global email classification system includes email classification servers, email classification clients, and other components. Personal email messages are in a special category. This invention includes a method to classify email messages into personal email messages and non-personal email messages. In an email classification system, an email message is processed by the email sender classification client before it is sent out. The email sender classification client requests a challenge object from the email classification server. The challenge/response process plus other factors determines the email classification. The challenge/response result is stored in the email classification server as an email data object.